Barman prepared repast after very little time (7)
I believe the answer is:
tapster
'barman' is the definition.
(tapster is a kind of barman)
'prepared repast after very little time' is the wordplay.
'prepared' indicates an anagram.
'after' means one lot of letters go next to another.
'very little' indicates taking the first letters.
The initial letter of 'time' is 't'.
'repast' with letters rearranged gives 'apster'.
'apster' after 't' is 'TAPSTER'.
(Other definitions for tapster that I've seen before include "Rat pest (anag.)" , "Bartender once" , "old barman" , "Old barperson" , "Bar employee" .)